The unique barcode that is displayed on each ticket can generally be scanned directly from a printed ticket or onscreen from a tablet or mobile phone at the event using the FooEvents Check-ins apps or FooEvents Express Check-in plugin.
We recommend using an external barcode scanner or high quality smartphone camera to scan barcodes. The performance of onscreen barcode scanning varies between devices, but we have not experienced any issues with onscreen scanning on our test devices (iPhone 6, Samsung Galaxy, Nexus etc).